Process for dyeing aluminum oxide layers



United States Patent 3,202,550 PROCESS FQR DYEENG ALUMENTUM UXIDE LAYERS Hans Grossrnann, flberwil, Basel-Land, and Heinz Keller, Basel, Switzerland, assiguors to Durand dz Hugueuin A.G., Basel, Switzerland, 2 Swiss company No Drawing. Filed Aug. 13, 1%2, Ser. No. 216,335 Claims priority, application Switzerland, Aug. 16, 1961, 9,5S3/61 12 Claims. (Cl. 148-61) The invention relates to a process for dyeing aluminium oxide layers produced on aluminium.

It is known that oxide layers produced on aluminium can be dyed, for example with inorganic pigment dyestufis. Organic dyestuffs, however, are preferably used to dye aluminum oxide layers, which are simpler to apply than inorganic pigment dyestulfs and further permit the production of numerous shades. Thus, a Wide variety of organic dyestuffs have already been proposed for the dyeing of aluminium oxide layers, varying namely both with respect to their dyeing properties and their chemical constitution. The acid, water-soluble, organic dyestuffs are primarily of practical importance.

It has now been discovered that organic dyestuffs containing at least one acid group of a pentavalent element of Group V of the Periodic System with an ordinal index between 14 and 52 are particularly suitable for dyeing aluminium oxide layers.

By aluminium oxide layers, such as come in question for the purposes of the invention, such oxide layers are to be understood which are able to take up (adsorb) organic dyestuffs as a result of their adsorption capacity and their large inner surface. Such oxide layers can be produced both by chemical methods, e.g. by oxidation with chromates, and primarily by anodic-electrolytic methods. Suitable anodic processes are, for example, the chromium, oxalic and, primarily, the sulphuric acid process.

By aluminium not only pure aluminium, is to be understood, but also alloys thereof with various elements, such for example, as with Cu, Mg, Mr, Si, Ni, Zn, Pb, Cd, Ti, which act in a similar manner as aluminium with respect to oxidation.

By aluminium oxide, the above described oxide layers on aluminium and alloys thereof are to be understood hereinafter.

The dyeing of aluminium oxide layers may be effected by impregnation, for example by painting, printing or spraying, or dyeing in a dye bath. The dyestufi is advantageously employed in a partially or completely dissolved form. For this purpose, both organic solvents such, for example, as ethyl alcohol, acetone or dimethylformamide, and inorganic solvents such, for example, as water, come in question, sofar as the dyestuff is at least partially soluble in the respective solvents. For practical and economical reasons, dyeing in an aqueous dye bath is primarily desirable.

Dyestuffs containing at least one of the claimed acid groups excel, as tests have shown, in their particularly high afiinity to aluminium oxide layers. Such dyestuffs have hitherto not been used for dyeing aluminium oxide layers.

It is further known that the affinity of conventional dyestuffs to aluminium oxide layers can be greatly impaired by even small amounts of foreign ions. One is therefore often forced to use softened water to prepare the dye baths and replace loss of water as a result of evaporation, which is uneconomical.

One is forced in practice to use large dye baths, by reason of the various shapes and sizes of the aluminium oxide articles to be dyed, so that generally, when dyeing aluminium oxide articles, only a small part of the dyestuif 3,Z2,55li Patented Aug. 24, i965 dissolved in the dye bath is extracted. Since, however, a renewal of the bath is uneconomical, one is forced to dye in the same bath, that is to say, the dyestuff solution is not renewed after the dyeing, but brought again to the original concentration by the addition of dyestutf. This dyeing process causes an increase of foreign ions which cannot be avoided in practice, for example by salts which are always present in the commercial dyestuifs, by salts resulting from the oxidation process and adhering to the aluminium articles, or by compounds used to adjust the pH value of the dye bath. Practice has shown that the presence of such salts can impede the drawing capacity (affinity) of dyestuffs so greatly that a complete renewal of the dye bath becomes necessary even if the original dyestutf concentration is still present.

It has now surprisingly been found that dyestuffs containing at least one acid group of a pentavalent element of Group V of the Periodic System with an ordinal index between 14 and 52 do not have this considerable, uneconomical disadvantage, but can be used dissolved in both hard water and water enriched with th usual salts. It was even noticed that the drawing capacity (affinity) of dyestuff solutions can, in certain cases, even be increased in the presence or upon the addition of certain salts.

Aluminium articles provided with an aluminium oxide layer, which have been dyed according to the process claimed, do not bleed when kept in water and upon sealing of the oxide layer. The bleeding was hitherto often not avoidable, even when taking all precautionary measures, whereby the production of uniform dyeings was rendered diiiicult.

The drawing capacity (allinity) of dyestuffs containing at least one of the above defined acid groups on aluminiurn oxide is further, contrary to most of the hitherto used dyestuffs, barely influenced by a pH value of the dyebath in the conventional range of 43. The often complicated adjustment and maintenace of a constant pH value of the dye bath is thus no longer necessary.

Aluminium oxide layers are usually dyed at temperatures between 55 and 65 C. since, when dyeing at room temperature, dyeings are generally obtained which are weaker or which bleed more strongly in water; Dyestuifs containing at least one of the above defined acid groups may, however, also be applied without disadvantage at room temperature.

Dyestuffs containing at least one of the above defined acid groups, when added in small concentrations to the sealing bath, further prevent the formation of oxide layers which can be rubbed off [Process according to F. Modic, Aluminium 35, 382 (1959) and 36, 457 (1960)].

Acid groups of a pentavalent element of Group V of the Periodic System with an ordinal index between 14 and 52 are, e.g., the primary and secondary phosphonic, arsonic, stibonic, thiophosphonic, thioarsonic acids and monoesters thereof; By primary groups of the formula AO(OH) and by secondary groups of the formula AO(OH) are to be understood, whereby A means P, As or Sb. By the monoester compounds of the formula AO(Ol-l) (OR) are to be understood, wherein R means an aliphatic or aromatic radical, preferably a hydroxy, alkyl, O-alkyl-, aryl or O-aryl radical, and by the thio compounds are such compounds to be understood, the O atoms of which are partially or entirely replaced by S atoms. The primary arsonic and stibonic acid groups are particularly suitable, and more particularly the primary phosphonic acid group. These groups may be linked, for example by an S, O or N atom to the dyestutf molecule. The link to a C atom is, however, particularly suitable. Various ones of the above mentioned acid groups may also be linked to the same dyestulf molecule,

The chemical constitution of the dyestuffs employed in p was produced. by

' ing in boiling Water.

accordance with the invention and containing at least one or the above defined acid groups is of subordinate importance with respect to the afiinity to aluminium. Widely varying dyestulf classes are therefore suitable such, for example, as nitro, triarylmethane, xanthene, acridine,

' arrrinoketone, quinoline, anthraquinone, phthalocyanine,

monoaz'o, disaz'o, polya'zo and azomethine dyestuffs. Combinations of two diflierent dyestufi classes are also suitable such, for example, as azoarithraquinone and azophthalo yanine dyestuffs. V Dyestuffs are further suitable which contain a complex-forming group, for-example an o oxyc'arboxyphenyl or an ozo-dioxyazo group, or a complexbound heavy metal. 1 a H Since dyeing in aqueous solution is of technical'impor tance, those dyestuffs are primarily of interestwhich con tain inaddition to the above-defined acid groups,'other water-solubilizing groups, in particular'sulphonic acid groups, to increase the water-solubility. If desired, however, one may also print anodically oxidized aluminium with a'dyestuif paste according to the film screen printing process. i

Dyestuffs which are suitable for the pr'ocess claimed are 7 only known from literature in a small number. They may beprepared, however, bymethods known per se. They may be constructed, for instance,.by starting from intermediate products contining one of the above defined acid groups. The above defined'acid groups can, however, also be introduced into the dyestufi molecule. A particularly of aluminium is completely decoloured in the sealing bath as a result of bleeding.

The dyestulf used in this example may be prepared as follows: 17.3 parts of 3-.aminobenzene-l-phosphonic acid are dissolved neutral in 200 parts of Water with sodium hydroxide solution. 25 parts by volume of hydrochloric acid (33% )are added and the solution is'diazotized after having been cooled to 5.l by the dropwise addition of an aqueous solution of 7.0parts of sodium'nitrite. The

diazo solutionis allowed to flow at 38 into a solution of 22.4 parts ,of 2-naphthol-6-sulphonic acid and 30 parts of sodium carbonate in; 350 parts of water. Upon completion, the solution is heated until the dyestuff dissolves,

100. parts of sodium chloride are added, and the precipisuitable process for producing the dyestufis used in accordance with the invention consists in reacting intermediate products or dyestufis containing a reactivehalo gen atom with aliphaticor aromaticiamino'or hydroxy compounds "containing one of the above defined necessary acid groups. On the other hand, compounds having a reactive halogen atom in addition to one of the above defined acid groups may also be reacted with intermediate products or dyestuffs containing amino and hydroxy 7 groups." Azo dyestuffs maybe obtained, for instance, by

- I the actionof a diazo component on a coupling component, at least. one of the twozcomponents containing at least one of the above defined acid groups. Such azo components may be prepared, for example, in the benzene, naphthaline, vacylacetylamine, pyrazolonei and ;quinoline seriesgSo' far as the azo; dyestuff formed contains one or mQre omp e o up ey'm y' v by a known methods ,intothe heavy metal compounds.

' In'the following examples, which are only intended to be illustrative of the invention, where nothing to the con- .traryjis mentioned; the parts mean partsby Weight, the percentages are percentages by weight, andthe temperatures are given in degrees centig'rade. r

j Q XAMPLEI. i A degreased piece of aluminium is anodicallyoxidized in 20% sulphuric. acid at a current density of 1.5 amp/ dm. some minutes at 18-20 to form an oxide layer having a thickness of 10 microns, isrinsed in running Water for 15 minutes. and then dyed in a dyebath which dissolving .1 partofthe dyestufi of the tormulaf in 1000 parts of non-softened waten'at a pH"o f'7,.0 land at roomtemperature for 30 minutes..-;A' vivid golden yellow dyeing is obtained which does not. bleed upon seala ve io m l is mp y d when a $03 ras in tsad i QSHZ t a a ld the dyeing is performed under the same conditions, the piece A deep blue dyeing is obtained. a

dissolved in IOOO parts of non-softened water.

Even with the addition of up to 15% sodium sulphate to: the dye bath' before dyeing, an equally strong dyeing isobtained. j If a dyestufl of the above, formula is used which'has a S O H group. instead'of the. PC H group, the piece of aluminium is dyed considerably fainter. In the presence of sodium sulphate, absolutely no colouring takes place.

The dyestutf used in this example may be prepared as follows? 30 'parts of 1-amino-4-bromo-anthraquinone-2e sulphonic acid, 26 parts of 3-aminobenzene-l-phosphonic' acid, 47parts of sodiumcarbonate and 3 parts of copper (I)-chloride are heated-in 800 parts of water for 20 hours 7 By the addition of. hydrochloric acid until an acid reaction to Congo red is'obtained, the dyestulfis precipitatedand obtained pure by dissolving the sodium s'alt in 'water 'and'then precipitating the same. Dyestuff sof the following composition .0. I NH;

and

Shade: violet ill-the same ;manner,- have similar which may be prepared properties. i

EXAMPLE 3 A piece of aluminium anodically oxidized according to Example 1 is dyed for 30 minutes at 60 and a pH of 7.0 in a bath containing 2 parts of the dyestuif of the formula .1 wherein CPC means a copper phthalocyanine molecule substituted in 3:3:3":3"-position, 100 parts of sodium chloride and 1 part of nitrilo-triacetic acid in 1000 parts of non-softened water. A vivid, turquoise blue dyeing is obtained. If the piece of aluminum is placed in nonsoftened Water Without sealing, no bleeding can be noted even after three days.

If the dyeing is performed under the same conditions but in a bath containing 2 parts of copper phthalocyanine- 3:3:3":3-tetra-sulphonic acid, aluminium is not coloured. On the other hand, if the dyeing is eilected under conditions suitable for dyestuffs exempt of phosphonic acid groups (i.e. at a pH of 5 and in the presence of softened water), a turquoise blue dyeing is also obtained. After being placed in non-softened Water, the piece of aluminium dyed in this manner is after one day partially and after three days completely decoloured.

The dyestuif used in this example can be prepared as follows: 29 parts of copper phthalocyanine are introduced into 220 parts of chlorosulphonic acid at 35 and stirred for 1 hour at 35 and for 4 hours at 135. After having cooled to room temperature, one pours onto ice, the precipitated copper phthalocyanine-3:3:3":3"-tetrasulphonic chloride is filtered off, slurried in ice Water and neutralized with sodium carbonate. An aqueous solution of 11.5 parts of aminornethane phosphonic acid and 35 parts of sodium carbonate are added and the mixture is stirred until the reaction is completed. The dyestuff is precipitated by the addition of hydrochloric acid and is recrystallized from water.

If 5.8 parts or 17.3 parts of aminomethane phosphonic acid are used instead of 11.5 parts of aminomethane phosphonoc acid, dyestufis are obtained Which are also suitable for the process claimed.

If, instead of the aminomethane phosphonic acid,

equivalent amounts of 3-amino-4-methylbenzene-l-phos- EXAMPLE 4 A piece of aluminium anodically oxidized according to Example 1 is dyed at 60 in a dyebath containing 5 parts of the dyestuif of the formula Cu O O SOsE l 1 in 1000 parts of water. A red dyeing is obtained which, compared with the comparable dyestuif exempt of phosphonic acid groups, excels by its deeper shade and lesser bleeding upon sealing in boiling Water.

The dyestuff used in this example may be prepared as follows:

26 parts of 3-nitro-4-chlorobenzene-l-sulphonic chloride are introduced in portions at 2D30 into a solution of 17 parts of 3'amino-benzene phosphonic acid in parts of Water. The pH value is thereby maintained at 7.5 to 8.5 with diluted sodium hydroxide solution. After the reaction is completed, the condensation product is separated oif by the addition of sodium chloride and filtered. The intermediate compound is heated under reflux in 100 parts of Water and 30 parts by volume of caustic soda lye (30%) for 3 hours, rendered acid to Congo red with hydrochloric acid and filtered off. The resulting product is introduced in portions into a boiling suspension of 30 parts of iron powder in parts of Water and re duced. 2 parts of sodium sulphite are now added, the suspension is rendered markedly alkaline to phenolphthalein with lye, one filters ofi from the iron residue and neutralizes the filtrate with hydrochloric acid. A solution of 3-('4'-oxy-3-aminobenzenesulfonylamino) benzene-1- phosphonic acid is thus obtained. A solution containing 34.4 parts of the above compound is diazotized at 5-10 by the addition of hydrochloric acid and 7 parts of sodium nitrite and introduced at 15 into a solution of 31 parts of 2-naphthol-3:6-disulphonic acid and 40 parts of sodium carbonate in 200 parts of Water. After the coupling is completed, the solution is neutralized With 80% acetic acid, 25 parts of crystallized copper sulphate are added, the whole is refluxed for 1 hour and the copper compound of the monoazo dyestuif is separated oh by filtration after the addition of sodium chloride.

Equivalent amounts of 3-aminobenzene arsonic acid or aminomethane phosphonic acid may be used with the same success instead of the Z-aminobenzene phosphonic acid.

EXAMPLE 5 1 part of dyestufi of the formula -N=N'- --AS O 3112 is dissolved in 20 parts of dimethylformamide and stirred into 80 parts of thickener (consisting of 8 parts of ethyl cellulose and 92 parts of xylene).

The paste is printed on anodically oxidized aluminium by the film screen printing process and dried in the air. The print is completed by sealing in boiling Water and purifying with benzene. An orange coloured print is obtained.

The dyestuif used in this example is obtained by coupling diazotized 4-aminobenzene arsonic acid and Z-naphthol.

If 4-aminobenzene phosphonic acid or 4-aminobenzene stibonic acid is used instead of 4-aminobenzene arsonic acid, dyestuffs with similar properties are obtained.

The dyestuffs used in this example may also be dyed cold on aluminium from a 1% solution in dimethylforrnamide.

EXAMPLE 6 Q-NHGNHGSOQNHCHgCHgPOgHi l l S0311 N0 in 1000 parts of Water. A yellowish brown dyeing is obtained which excels in its Water-fastness.

-- V 3,202,55d 1 Q The dyestufl. used in this example can l e prepared as follows 25.6 parts of 3-nitro-4-chlorobenzene-l sulphonic chloride are introduced at 3040 in portions into a solu tion of 12.5 'parts of 2-aminoethane phosphonic acid in 100 parts of water; A pH value of 7-8 is maintained duringthe' said introduction by the dropwise addition of 2N sodium carbonate solution. After the reaction is completed, the solution is rendered markedly acid to Congo red with hydrochloric acid, the precipitated product is filtered off and recrystallized from alcohol. 7

A 34.5 parts of the'resulting 2-(3'-nitro 4'-chlorobenzene sulfonylamino)-ethane-1-phosphonic acid and 26.5 parts of 4-aminodiphenylamine 2-sulphonic acid are dissolved cold and neutral in 250 parts of water with caustic soda lye. 30 g. of sodium bicarbonate are then added and the wholev is refluxed ,until the reaction is -completed. 'The nitro dyestufi is separated oif in conventional manner and freed of bye-products.

. Instead of 2-(3-nitro-4-chlorobenzene sulfonylamino)-- ethzine-l-phosphonic acid, equivalent amounts of 3-(3- nitro-4'-chlorobenzene sulfonylamino) benzene-1 phos- 8 sulphite solution (40%).containing, 19 parts of sodium carbonate and 30 parts of ice. The reaction mixture is allowed to warm to room temperature while stirring and the temperature is increased to 50 after 2 hours. After the. dropwise addition of 61 parts by volume of concentrated sulphuric acid, the mixtureis brought to the boiling point and this temperature is maintained for 4 hours. The cooled solution of phenylhydrazine-El-phosphonic acid is rendered slightly alkaline by the dropwise addition of concentrated caustic soda lye, 13.8 parts of acetoacetic acid ethyl ester are, added at 60, the pH is adjusted to .12'with concentrated caustic soda lye after 1' hour and the solution isheated to -95-100 for 2 hours.

phonic acid, -1-arsonic acid or -1-stibonic acid maybe used with thesame success.

. 7V "EXAMPLE 7 A 'sheetof aluminium is oxidized at 95 for 10 minutes "in a solution consisting of 50parts of sodium carbonate (anhydrous), parts of sodium chromate and 1000 parts of water, rinsed for 10 minutes in running water and then dyed for minutes at 60 in a dyebath consisting of 5 parts of dyestuflf of the formula Nun-Goo V soarr dissolvedin 1000 parts of water. A mat, yellowish olive green dyeing is obtained which excels in its water-fast ness.

The dyestuif used in this example may be prepared as follows: 15.5 parts 'of 4-aminonaphthalic acid 6-si1lphonic acid, 8.6 parts of 3 aminobe'nzene phosphonic acid and 30 parts of sodium bisulphite (anhydrous) are refluxed for 12'hou'rs in 200' parts of 'water. The dyestuff is isolated as usual. 7 r

V EXAMPLE H ;I -Adegreased piece of aluminium isianodically oxidized in an oxalic acid solution consisting of 30 parts of oxalic acid, 20 parts of potassium oxalate and .1000 parts of water at a current densityof; 1.5 'amps./dm. 'and a temperature of 60 for 30 minutes to form an oxide lay'erf having a thickness of approximately :12 microns,

rinsed for 10 minutes in running water and then 'dyed at in a dyebath prepared by dissolving 1 part of dyein 1000 partsof water. A' g olden yellow dyeing is obtained whichlexcels in its water-fastnessiwhen kept underwater and sealed in boiling water.

The dyestufi used in this' examplel;maybe prepared 'are' dissolved in 400 arser water at 60.

After having cooled, the solution is rendered acid to Congo red. by the addition of 300 parts by volume of 2 N sulphuric acid. The precipitated residue is filtered oif, washed withwater and dried.

The diazo compound preparedfrom 27 parts of 2- amin'o-phenol-4:6-disulphonic acid is coupled at room,

temperature in the presence of sodium acetate with 25.5 parts; of 1-pheny1-3-rnethyl-5-pyrazolone-3 1 phosphonic acidjobtained as intermediate product, and the resulting dyestuif is converted into the complex metal compound of the above formula by heating with 25 parts of crystal- 7 'lized copper sulphate.

. V 7 EXAMPLE ,9

V A sheet of aluminium is anodically oxidized for 60 minutes ina solution consisting of 5 parts of chromic acid, 0.5 part of oxalic acid and 0.3 part of boric acid at 40 and with a current density of 1 amp/din. and a voltage of 25-40 volts, rinsed for 10 minutes in running water and thendyed at 60 'in a dyebath produced by dissolv ing 1 part of dyestufi of the formula in 1000 parts of water." A matfred dyeing: isobtained which, compared to the'dyeingproduced byz the come parable'dyestuff exempt of phosphonic acid groups, excels in its markedly improved water-fastness and its deeper shade.

Theidyestufi used in this'example may be prepared as follows; 20.4; parts of the mono'jazo dyestuii prepared according to Example l'from diazot'ized' 3 -aminobenzene l-phosphonic acid and "2-naphthol-6-sulphonic acid i 13.8 parts of crystallizedcopper sulphate .and 15 parts of crystallized sodium acetate are then added. 14.1 parts of hy- 'drogen' peroxide (30%) dissolved in- 50 parts of water as follows: 17.3 parts of 3-aminobenzene-l-phosphonic :acid and 7' parts of sodium nitrite are dissolved neutral in 100 parts of water by the addition of sodium carbonate. This solution is added dropwise to a mixture of parts of ice and 12.5 parts of, concentrated sulphuric acid, and diazotized at 0-5 The resulting .diazo solution is added at 10 to 80 parts by volume of sodium biare added dropwise within 30 minutes, the temperature is maintained at '60" for 2 hours, the solution is thenf tion of 1.3 parts of nitrilo-triacetic acid.

7 EXAMPLE 1 0 A sheet'of aluminium anodically oxidized according to'Example l is dyed for 30 minutes at 60 and with a pH of 55 in 'a'bath containingdtliparts of the dyestufi of the formula. 5 r

heated to and the dyestuff salted out after the addi- V V I 16 parts of -1-phenyl-3 methyLS-pyrazonone-3phosphonic acid are obtained.-

dissolved in 1000 parts of Water. A greenish yellow dyeing is obtained which excels in its non-bleeding when kept under water and upon sealing.

The dyestufl used in this example can be prepared as follows: 27.3 parts of quinophthalone are introduced at 25 into 500 parts of chlorosulphonic acid and stirred for 1 hour at 25 and for 4 hours at 130. After having cooled, the mixture is poured into ice and the precipitate sulphonic chloride is filtered oil. The moist sulphonic chloride is then immediately 'slurried in 200 parts of water at 0, neutralized with sodium bicarbonate and an ice cold solution consisting of 17.3 parts of 3-arnino- Table Example Constitution of the dyestuff Shade produced $113 0 H NEE 11 N=N N=NONO Bluish black.

C H 0 E $11 12 l *=N- N=NONH Greeuish black.

HO3S- S 03H OH ITTHC O C H 13 CH3GN=N N =N Reddish blue.

I P 0 3 2 H 0 3S S 0 311 S 0 3H 14 =0 H- Yellow.

ASOaHg H 0 3'3 (HI I 15 N=NP O (OH) Orange.

1 HO 3S 2 N Hg 16 N =N- Sb 0 H, Brownish orange.

l S 03H 17 ON=N Reddish violet.

18 HO sS C HTNON=NOAS 0 3H: Golden yellow. 7

Table-Continued Example Constitution of the dyestutf Shade produced 0 H O H 23 2OeP -N=N N=N P 0 Reddish violet.

HOaS NH- S 0311 O0uOj|JCH l 29 02N N=NCC ON HCH2. P 03H; Yellowish orange.

Produced from the reaction product of diketene and amino-methane phosphonic acid by coupling with diazotized fi-uitro-2-aminophenol-dsulphonic acid and subsequent complexing with copper.

O Ou O I l 30 H058 N=N= Bluish red.

i 1 303E SOQNHCH2PO3HQ Produced by reacting Zoxy-Lcorboxynephthaline-G-sulphonio chloride and aminomethane phosphonic acid, splitting ofi the carboxy group, coupling with diazotized 2-aminophe11o1-426-disulphonic acid and subsequent oomplexing with copper.

0 Cu 0 I 1 31 2 zAS N=N Reddish violet.

l S 03H Produced from dyestuii according to Example 27 by oxidative complexing with copper. H20a|S C|)-C1lOO('1 32 Os zNHOHQPOSHQ R d.

Produced by condensing i-chloro-S-carboxybcnzene sulphonic chloride and aminomethane phosphonic acid, reacting the labile chlorine atom with aqueous ammonia in the presnecc of copper powder in an autoclave at 135, cliazotizing the resulting amine and coupling with 2-0xynaphthaliue-3:fi-disulphonio acid and converting into the complex copper compound.

33a Copper complex of the dycstuli oi the following formula,

0 H OH l ASOziHg S 0311 33b Chromium complex of the dycstufi according to Example 33a Violet.

33c Cobalt complex of the dyestufi according to Example 33a Reddish violet.

33d Nickel complex of the dyestufi according to Example 3% Red.

34 Reddish violet.

Produced according to the process of German Letters Patent 870.270 and 895.041

wherein A rcpresents'a member selected from the group consisting of P, As and Sb. 7 i

2; A process for'the dyeing of aluminum oxide layers on a metallic base material selected from the group consisting of aluminum and aluminum containing alloys which comprises contacting the said oxide layer with an, organic dyestufi which contains at least one'substltuent 7 group of the formula Table Continued Example Constitution of the dyestuff V Shade produced NH, II I 85 8031-1 7 Green.

I o NEON: roam (1H3 I V 0 NH: 7 V

as sou: NH, Bluish green.

I OCH I r N N 1 p 1) NH Nail o-NHONQI AsO H,

V a V SO H r (EH3 t '37 HmsQNH- 1 03H, Yellow. 7

NO: V V

s8 QNHQNHQ-MOM: Y ll wis r wn.

SOzH l fOr V a9 oro r V 7 Bl 'h r -so,NH-N=N- roan, ms green V wherein C PC means a copper phthaloeyanine molecule substituted in 3:4:4:4 positlon V 40 "H:0:PCH; 3N=N Orange. H

- r v 80311 41 =NO H V Goldenyellown xc c v What we claim is: a 7 .wherein V t A process for the y g of alummum x e y V A represents a member selected from the group conon a metallic base material selected from the group con-' sisting of P, As and Sb, and sisting of aluminum f l P fmfltammg P Y R represents a member selected from the group conwhich comprises contacting the sa1d oxide layer w th an ,sisting of OH, alkyl, olk l, l d 0 1 organic dyestufl which contains at least one substituent 3. A process for thcdyeing of aluminum oxide layers group of the formula V on a metallic base material selected from the'group ,conj g j OH' 7 sisting of aluminum and aluminum containing alloys r t r r which comprises contacting the said oxide layer'with an' organic dyestufi which contains at' least one substituent group of'the formula v p I A==O whereirrA represents a member selected from the group consisting of P,'As and Sb.

7 4. A process for the dyeing of aluminum oxide layers on'a metallic base materialselected from the group consisting of aluminumv and aluminum containing alloys ;which comprises contacting the said oxide layer with an it? organic dyestufi which contains at least one substituent group of the formula 5. A process for the dyeing of aluminum oxide layers on a metallic base material selected from the group consisting of aluminum and aluminum containing alloys which comprises contacting the said oxide layer with an organic dyestufl of the formula /OH DA=0 wherein A represents a member selected from the group consisting of P, As, and Sb, and

D represents the monovalent radical of an organic dyestufi selected from the group consisting of nitro, triarylmethane, xanthene, acridine, aminoketone, quinoline, anthraquinone, phthalocyanine, monoazo, disazo, polyazo, and azomethine dyestufis.

6. A process as in claim wherein A represents P.

7. A metallic base material selected from the group consisting of aluminum and aluminum containing alloys having an aluminum oxide surface dyed with an organic dyestuff which contains at least one substituent group of the formula wherein A represents a member selected from the group consisting of P, As and Sb.

8. A metallic base material selected from the group consisting of aluminum and aluminum containing alloys having an aluminum oxide surface dyed with an organic dyestufi which contains at least one substituent group of the formula wherein A represents a member selected from the group consisting of P, As, and Sb, and R represents a member selected from the group consisting of OH, alkyl, O-alkyl, aryl and O-aryl. 9. A metallic base material selected from the group consisting of aluminum and aluminum containing alloys 18 having an aluminum oxide surface dyed With an organic dyestufi which contains at least one substituent group of the formula wherein A represents a member selected from the group consisting of P, As, and Sb.

ll A metallic base material selected from the group consisting of aluminum and aluminum containing alloys having an aluminum oxide surface dyed with an organic dyestuif Which contains at least one substituent group of the formula 111. A metallic base material selected from the group consisting of aluminum and aluminum containing alloys having an aluminum oxide surface dyed with an organic dyestutl which contains at lea-st one substituent group of the formula /OH DA=O wherein A represents a member selected from the group consisting of P, As, and Sb, and D represents the monovalent radical of an organic dyestuif selected from the group consisting of nitro, triarylmethane, xanthene, acridine, aminoketone, quinoline, anthraquinone, phthalocyanine, monoazo, disazo, polyazo, and azomethine dyestuffs. 12. A material as in claim 11 wherein A represents P.

References Cited by the Examiner UNITED STATES PATENTS 1,962,339 6/34 Cotton 148-6.1 2,228,259 1/41 De Long 148-61 FOREIGN PATENTS 1,042,523 11/58 Germany.

OTHER REFERENCES Kosolapoft et al.: J. Am. Chem. Soc. (1953) 4847-9, QD 1. A5.

RICHARD D. NEVIUS, Primary Examiner.

WILLIAM D. MARTIN, Examiner. 

1. A PROCESS FOR THE DYEING OF ALUMINUM OXIDE LAYERS ON A METALLIC BASE MATERIAL SELECTED FROM THE GROUP CONSISTING OF ALUMINUM AND ALUMINUM CONTAINING ALLOYS WHICH COMPRISES CONTACTING THE SAID OXIDE LAYER WITH AN ORGANIC DYESTUFF WHICH CONTAINS AT LEAST ONE SUBSTITUENT GROUP OF THE FORMULA 